Evening star. [volume] (Washington, D.C.) 1854-1972, 1887-08-13
GENERAL AND LOCAL STORNfSs
How They are FOreiOld-The Old Fable
OF Heat Lightning.

GENERAL AND LOCAL STORMS.
How They are Foretoid-The Old Fable
Of Heat Lightning.
To the Editor Of the EVENING stan:
Prior to having the weather map we knew little
about storms even ofmeteorological conditions;
the map has been the one thing that has enlight-
ened us in regard to the atmosphere OF our globe.
That quotation from the Psalms s'the dew Of thy
birth is the womb OF the morning" is most appli-
cable In this case. The establishment Of the map
was the event that dispelied the darkness in this
department., and drew the veil whereby we could
become familiar with this all important branch OF
the wonderful creation which surrounds us
In order to understand the atmospheric changes
which we term storms, we must refer to the map.
On 1t We will see various lines or irregular curves.
One set viii be found to be quite heavy and prom
tnent while the other will be found to be dotted
and much lighter. The heavy solid lines indicate
the different degrees OF barometric pressure; the
gn sotted lines ss 1h Inc
lar and more or less Irregular about the centers OF
the high and low pressure. The dotted, or
are necessarily fewer in number than the heayy
lines, or isobars Sometimes they are in
ss circles down iUwsa tn form su t5 se
up toward the northeast. Their contour
depends upon the ''highs' and the slows" II one
OF these factors lay we'll TO the south or north and
the other In the counter section OF the country,
the lines viii be quite parallel; but, IT, say the
Flows are respectively In the northeast and north
west, and "high" reaches well to the soul h, then
these dotted, isothermal, lines will form great CTR
Giles In horseshoe form. 1his latter condition will
show that at the time 1t Is 50 warm in the north,
say as high as As degrees even SO degrees N. L.
as 1t is in the cotton States.
By observing these lines and the positions Of the
understand the meteorological conditions OF The
whole territory OF the. United States, and why in
some sections it Is cold or warm, and In others,
why general or local storms prevail.
The general storm is common with all seasons
OF the year. still it Is more prevalent in the fall,
winter and spring; While the 'local" is pecu.
liar to the warmer months, say, late in the spring,
during the summer. and in the early fall.
When. on the map, the dow" Is well concen-
trated with a center, 29 and three or four tenths
or less, and it is moving with speed Of from "a
to 40 miles an hour general storm will take place
over a wide extent OF territory, covering,
thing to note is that sometimes at the very center
OF ''low" it may be clear, Tor the reason that The
clouds have dropped their fairness" before reach
ing this point; but more frequently the heaviest
rains occur at the center There Is no law In the
case beyond the fact that the heavy rain comes
from the lui cloud and AFTER the cloud has depos
tied its moisture that ends 1t, cloud and ALL Ger
tain parties have endeayored TO bring meteorology
down to mathematics, but 1t has proved a most
stubborn department Oh nature to regulate by that
science. Might as we'll by mathematics try to
prove what viii be the shape OF the next cloud In
the ARMAMENT or the SIZE color, sex, and condition
or the next individual whom we will meet On the
street, The changes are so infinite that no ar1th-
metic OF man Cali ever hope 10 figure them out.
The "loea l., storm" Is peculiar TO the warmer
north ''lOw." In the cooler months the heat from
the sun seems to be more concentrates; in the
the cooler months, II we will but look on the map,
we will see that the gradients" are together
while during the warmer months they are far
apart. general storm" is stormy condition
over wide expanse OF territory. local" is
| when it rains here and there for short time at
different hours OF the day over an extended ter
ntOry.
Before the age OF the map we used to hear much
about cheat lightning" as though there was some
peculiar electrical condition That generated on,y
there is no such phenomenon, but rather that 1t is
the result OF .'local' at distance too far away
to hear the thunder, perhaps 20 or even 100
miles away. While the thunder and lightning is
one OF the most peculiar features OF local" we
sometimes have the "IOcal" without 1t, and at
other times have the thunder and lightning with
the general storm, whicrwill occur when .slow'
Is On north line or travelling toward north line.
But for the local" the Southern States in particu-
lar would suffer greatly for want Of rain during
the summer months. The ''lOcal" is the tempo
rary relief from time to time through the warmer
seasons OF the year, the subtiute for the full RAIN
From the map We know the general lines within
which the '0cal" will occur but we cannot speak
OF 1t with the certainty We can OF the general
Is confined to small area, or number OF small
areas, that one day 1t Will pass over one locality
and the next day over another, and pass within a
quarter OF q mile OF q place and give no Sign to
the immediate neighborhoOd beyond the so-called
cheat lightning" The map relegates cheat light
ming" to the fabulous grounds, thoroughly explains
what the phenomenon is due TO, but depriveS it OF
its ancient absurd position among cultivated So
ciety.
During the thunderstorm we know that the
lightning will strike somewhere within the radius
OF the storm, but cannot locate 1t; so with the
''lOcal Storm" We know that 1t will take place
somewhere WITHIN the outer lines Of "low," but
cannot say over what particular square mile the
storm will pass In all nature there Is nothing
more uncertain than the hour and spot, when and
no wi n in
the outer lines OF '0w," but further than this we
cannot, with certainty, Say. LP.N.